Blending pump assembly

ABSTRACT

A blending pump assembly for accurately maintaining the proper ratio of two fluid components. Flow of a first fluid is utilized to drive a fluid motor, which in turn drives a pumping mechanism to inject a proportional amount of a second fluid into the flow of the first fluid. The fluid motor and pump are sized so that a predetermined ratio between the two fluids is maintained regardless of changes in pressure and flow rate of such first fluid.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of co-pending U.S. patentapplication Ser. No. 11/593,826 entitled “Blending Pump Assembly,” nowU.S. Pat. No. 7,404,705, filed with the U.S. Patent and Trademark Officeon Nov. 7, 2006 by the inventor herein, which application is acontinuation of U.S. patent application Ser. No. 10/719,605 entitled“Blending Pump Assembly,” now U.S. Pat. No. 7,131,826, filed with theU.S. Patent and Trademark Office on Nov. 21, 2003 by the inventorherein, which application is based upon and claims benefit of copendingand co-owned U.S. Provisional Patent Application Ser. No. 60/428,115entitled “Blending Pump Assembly”, filed with the U.S. Patent andTrademark Office on Nov. 21, 2002, by the inventor herein, thespecifications of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention disclosed herein relates generally to a proportioning pumpassembly, and more particularly to a pumping apparatus that maintainsthe ratio of two pumped fluids, which ratio is unaffected by alterationsin the pressure and velocity of the flowing fluids.

2. Background of the Prior Art

Several devices have been developed for injecting predeterminedquantities of liquid additives into a liquid flow stream. For example,beverage dispensing valves that provide for the mixing of carbonatedwater and syrup to produce a dispensed beverage are well known in theart. Other applications such as adding medication to drinking water withsuch additives as chlorine or iodine and adding fertilizer concentrateto irrigation water are similarly well known.

A number of fluid pumps have been designed that inject an additive intothe primary fluid stream where the primary fluid provides the motivefluid for activating the additive injection pump. For example, U.S. Pat.No. Re. 35, 780 to Hassell et al. discloses a beverage dispensing valvehaving two sets of oval gears in which the ratio of two liquid beverageconstituents is maintained by the interaction of the oval gear pairs,which are sized so that the desired ratio is maintained. Flow isregulated through use of solenoid operated pallet valves for each liquidcomponent.

U.S. Pat. No. 3,821,963 to Olsen et al. discloses a liquid proportioningapparatus for injecting a liquid into the flow of a driving liquid. Theapparatus uses an eccentric paddle wheel as the fluid motor to drive aseparate pump for a second liquid to be injected into the driving flow.

U.S. Pat. No. 6,357,466 to Walton et al. discloses an apparatus forgenerating a mixture of a first fluid and a measured quantity of asecond fluid in a fluid stream. The gears of a flow meter rotate when afirst fluid is passed through the flow meter. A shaft connectedcoaxially with a gear of the flow meter is connected with a gear of acavity pump for a second fluid so that the second fluid is pumpedthrough the cavity pump when the first fluid is directed through theflow meter.

While the above-mentioned compound motor/pump assemblies have beengenerally satisfactory to enable a driving fluid to be used as themotive force to drive a fluid motor which in turn drives a proportionalpump, these devices have not enjoyed significant commercial success.While positive displacement pumps, such as gear pumps, may at times havethe capacity to be used as a fluid motor, their design typically enablesleakage past the gears between the gear teeth and the housing, andbetween the gear sidewalls and the housing. For mixing applicationsrequiring precise mixing ratios, this leakage (and the variable mixingratios that result) can render such assemblies useless. Unfortunately,manufacturing the gear pump components with ultra-tight tolerances tominimize such clearance often increases the cost of such assemblies torender them uneconomical. Moreover, very small clearances may result inhigh friction and difficulty in getting the motor started at low fluidpressures. Still further, prior art fluid motor and pump assemblies havetypically been provided in configurations that limit their adaptabilityto varied mixing ratios due to a fixed relationship between the rate ofrotation of a driving gear in the fluid motor and a driven gear in thefluid pump, and thus fail to provide a practical pump assembly enablingcustomized mixing proportions to be obtained. It would be advantageousto provide a means to adjust the flow proportion in a fast, easy manner.Accordingly, there remains a need for an apparatus that enablesconsistent, direct proportioning of flow of two liquids independent ofthe pressure and velocity of the driving liquid while enabling both fineand gross adjustment of the flow ratio in a simple manner, but of asufficiently simplistic construction so as to maintain ease ofmanufacturing and low cost.

SUMMARY OF THE INVENTION

The blending pump assembly of the instant invention comprises a fluidmotor, the motor having an inlet fluidly connected to a source of afirst fluid and an outlet, a pump having an inlet fluidly connected to asource of a second fluid and an outlet, such fluid motor beingoperatively engaged with such pump through a drive which transferstorque from the fluid motor to the fluid pump, the fluid motor and pumpbeing interconnected in such a way that a predetermined ratio betweensuch first fluid and such second fluid is consistently maintained,irrespective of the pressure and velocity of the driving liquid. In afirst exemplary embodiment, the blending pump assembly may be providedan internal recirculation channel controlled by a valve to enableadjustment of the fluid proportions. In a second exemplary embodiment,the blending pump assembly may be provided with modular quick-connectfluid pump blocks that provide varying flow rates for a given angularvelocity of the driving gear of the fluid motor. Likewise, the blendingpump assembly may simultaneously provide both a recirculation channeland a modular quick-connect fluid pump block to enable both fine andgross adjustment of the ratio between dispensed diluent and concentrate.

The blending pump assembly described thus provides proportioning of twofluids in a tightly controlled manner, and may provide adjustment ofsuch proportion for fine and gross control of the ratio of such twofluids.

The compound motor/pump structure allows torque produced from the shaftof a fluid motor assembly to be used to drive a pump assembly connectedthereto in such a way that the output from the pump maintains a desiredproportion to the output of the fluid motor, irrespective of the flowstherethrough. The first fluid motor assembly is preferably driven byfluid pressure from a first fluid directed through an inlet port, whichflow in turn drives the shaft of the fluid motor assembly. The torquegenerated by the fluid motor is translated from the shaft to an impellerin the connected pump. A fluid motor body includes an inlet for a firstfluid and a corresponding outlet, while the pump body includes an inletfor a second fluid and a corresponding outlet.

In one embodiment, the first fluid inlet and outlet on the fluid motorbody are in fluid communication with one pair of circular gearspositioned within a fluid chamber in the motor, and the second fluidinlet and outlet on the pump body are in fluid communication with asecond pair of circular gears positioned within a fluid chamber in thepump. The first pair of circular gears comprises a gear motor, while thesecond pair of circular gears comprises a gear pump. Alternately, thegear pairs may be replaced with a single gear element in either or bothof the pump and motor assemblies, such as an eccentrically mountedimpeller. Each gear or gear pair, as the case may be, preferably rotatesin its own housing, fluidly separate from the other gear pair.

In another embodiment, the fluid inlet and outlet on the fluid motorbody are in fluid communication with a plurality of reciprocatingpistons connected to a crankshaft for providing rotary movement of adrive shaft. The drive shaft, in turn, is operatively connected to thefluid pump.

In one aspect of a preferred embodiment of the invention, arecirculation channel is provided in the pump assembly that enables fineadjustment of the compound motor/pump output. More particularly, a “tee”connector may be positioned in the flow line of the pump, downstream ofthe pump outlet, which allows fluid communication between the pump flowline downstream of the pump and the pump flow line upstream of the pump.A needle valve or similarly constructed flow control device may bepositioned in the flow branch interconnecting the downstream line withthe upstream line. In this way, minute adjustment of such flow controldevice may bleed off a portion of the fluid output from the pumpassembly, directing such fluid back to the pump input, and in turnenable fine adjustment of the amount of fluid dispensed from the pumpflow line for a given amount of first fluid passing through the fluidmotor.

In an aspect of another embodiment of the invention, gross adjustment ofthe proportional flow of a first fluid to a second fluid may be providedin a simple adjustment step. More particularly, the pump housing may bepivotally attached to the motor housing, and an intermediate drivemechanism, such as a gear train, may be provided between the two suchthat torque from the fluid motor drive shaft is transferred to the driveshaft of the driven member of the pump through such gear train. Thegears between the two housings may be selected to provide the desiredproportional speeds of the motor and pump. Moreover, because the pumphousing is pivotally mounted to the motor housing, the pump housing maybe pivoted to allow access to and replacement of the gears of the geartrain, and thereafter pivoted and locked back into a position in whichthe gears of the gear train engage one another, thus enabling grosschanges in proportioned flow rates to be achieved in a quick and easymanner. Alternately, the gear train may remain fixed, and the drivengear or gears within the pump may vary from pump housing to pumphousing, such that switching out one pump housing for another mayprovide changes in proportioned flow rates.

In operation of a first embodiment, a pressurized first fluid isprovided to the fluid motor fluid channel inlet and is delivered to theoperative motor member(s) therein for providing rotation thereof. Thefirst fluid then flows out of the fluid channel outlet. It can beunderstood that, as one of the rotational members of both the fluidmotor and the fluid pump is on a common rotating shaft (or operativelyengaged with one another through a connecting mechanical drive such as agear train), the pressurized first fluid provides for the driving forcefor the gear pump for the second fluid. The operative members aredimensioned such that, for each revolution of the common shaft, apredetermined ratio of such first and second fluid is delivered.Moreover, such ratio is maintained regardless of the rotation rate ofthe members. The pump output may be finely adjusted by permitting aportion of the output to recirculate back to the pump inlet therebyreducing the quantity of such second fluid injected into the firstdriving fluid stream, and may be grossly adjusted by replacing drivegears between the fluid motor and fluid pump or by replacing the entirepump housing with a different capacity pump. In addition, as themember(s) of the fluid pump serve as a pump, it is not necessary topressurize the second fluid source for the delivery thereof to theblending pump assembly.

Notably, with respect to the above-described embodiments, the connectionbetween the fluid motor and pump is one of a direct drive engagement,such that a desired proportional flow may be maintained at all times,irrespective of the pressure or velocity at which the driving fluidflows through the fluid motor. Moreover, the mechanisms provided hereinfor both fine and gross adjustment require few parts, such that thecompound motor/pump assembly of the instant invention requires lessmaintenance, and may likewise be provided at lower cost, than priorknown blending apparatuses. Still further, the features of fine andgross adjustment of proportional flow rates set forth herein enablesmuch finer proportioning control than previously known blendingapparatuses, and thus may be used in applications requiring very largeproportioning ratios.

The various features of novelty that characterize the invention will bepointed out with particularity in the claims of this application.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features, aspects, and advantages of the presentinvention are considered in more detail, in relation to the followingdescription of embodiments thereof shown in the accompanying drawings,in which:

FIG. 1 is an exploded perspective view of a blending pump assemblyaccording to one embodiment of the instant invention.

FIGS. 2 and 3 are cross section views of the blending pump assembly ofFIG. 1.

FIG. 4 is a cross section view of the pump portion of the blending pumpassembly of FIG. 1.

FIG. 5 is a cross section view of a vane pump or motor assemblyaccording to an alternate embodiment of the instant invention.

FIGS. 6 a and 6 b are exploded and sectional views of a screw pumpassembly according to another embodiment of the instant invention.

FIGS. 7 a and 7 b are exploded and sectional views of a piston pumpassembly according to another embodiment of the instant invention.

FIGS. 8 and 9 are exploded and sectional views of a blending pumpassembly according to another embodiment of the instant invention.

FIG. 10 is an exploded view of the blending pump assembly of FIG. 8,showing another feature of the instant invention.

FIG. 11 is a sectional view of an alternate embodiment of the fluidmotor assembly.

FIG. 12 is a schematic drawing of a first and second embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention summarized above and defined by the enumerated claims maybe better understood by referring to the following description, whichshould be read in conjunction with the accompanying drawings in whichlike reference numbers are used for like parts. This description of anembodiment, set out below to enable one to build and use animplementation of the invention, is not intended to limit the enumeratedclaims, but to serve as a particular example thereof. Those skilled inthe art should appreciate that they may readily use the conception andexemplary embodiments disclosed as a basis for modifying or designingother methods and systems for carrying out the same purposes of thepresent invention. Those skilled in the art should also realize thatsuch equivalent assemblies do not depart from the spirit and scope ofthe invention in its broadest form.

A first preferred embodiment of the compound motor/pump assembly of theinstant invention is shown in FIG. 1. A blending pump assembly,generally designated as 10, includes a lower gear motor assembly 12 andan upper gear pump assembly 15. Lower gear motor assembly 12 comprisesgear motor body 17 and cover 18, the motor body 17 having an inlet fluidchannel 21 and an outlet fluid channel 24 (best seen in FIG. 2). Inletfluid channel 21 may be in fluid communication with a pressurized sourceof a first fluid as shown in FIG. 7. Motor body 17 further includes acavity 27 wherein a first pair of gears 30, 31 is nested. Gears 30, 31may be circular gears having a plurality of teeth about their periphery,such that the teeth of gear 30 intermesh with the teeth of gear 31. Inthe particular embodiment depicted in FIG. 1, shaft 34 is rotativelysecured to motor body 17 and fixedly secured to gear 30, and extendsfrom gear 30 upward through aperture 36 in cover 18 to provide a driveaxle 39 for upper gear pump assembly 15. Gear 31 freely rotates on shaft35, rotatively secured between motor body 17 and cover 18.

Notably, alternate fluid motor constructions may likewise be usedwithout departing from the spirit and scope of the invention. Forexample, instead of gears 30, 31, a vane pump, a flexible rotor pump, orsimilarly configured pump assemblies capable of being driven by a motivefluid and transferring torque to a drive shaft 39 may be used for motorassembly 12.

Referring to FIGS. 3 and 4, gear pump assembly 15 comprises a gear pumpbody 42, to which a cover 43 is attached (FIG. 1). A second pair ofgears 46, 47 is nested in pump body 42. Gears 46, 47 may be circulargears having a plurality of teeth about their periphery, such that theteeth of gear 46 intermesh with the teeth of gear 47. Gear 46 issecurely attached to drive axle 39 such that rotation of gear 30 causessimultaneous rotation of gear 46. A seal 48 in aperture 36 may beprovided for preventing fluid communication along shaft 34 betweencavity 27 and gear pump body 42. Gear 47 freely rotates on shaft 49,rotatively secured between pump body 42 and cover 43. Pump body 42 hasan inlet port 51 and an outlet port 52 creating a flow channel 55through gear pump assembly 15. Inlet port 51 is in fluid communicationwith a source of a second fluid as shown in FIG. 12. Such second fluidsource need not be pressurized.

In one embodiment of the invention, a recirculation channel 58 isprovided in pump body 42 having an adjustable flow control device, suchas valve 60, to adjust flow through recirculation channel 58. Valve 60may, for example, comprise a valve stem 62 extending through gear pumpcover 43 (best seen in FIG. 1) and a valve handle 65 to permitadjustment of flow through valve 60. Valve 60 may be any appropriatetype of flow control device having throttling characteristics and ispreferably a needle valve enabling fine control of flow throughrecirculation channel 58. Flow through recirculation channel 58 is inthe direction indicated by arrow 69 in FIG. 3.

In an alternate embodiment, the fluid motor, the pump, or both may beother than gear assemblies, in which the fluid motor and pump have acommon rotating shaft. For example, a vane pump assembly, as illustratedin FIG. 5, can be used as the fluid motor, the pump, or both. Such avane pump assembly 70 may comprise body 71 having an inlet fluid channel72 and an outlet fluid channel 74. A slotted impeller 76 having aplurality of vanes 78 is eccentrically supported on shaft 80. Shaft 80is rotatively secured to body 71. A seal 81 may be provided to preventfluid leakage along shaft 80. The impeller 76 is located close to body71 so a crescent-shaped cavity 83 is formed. Vanes 78 fit within slotsof the impeller 76 and are configured to extend into such cavity 83 toform a slideable seal against body 71.

When vane pump assembly 70 is utilized as a fluid motor, inlet fluidchannel 72 may be placed in fluid communication with a pressurizedsource of a first fluid (see FIG. 12). The pressurized fluid enters theinlet fluid channel 72 and impinges on a first of such plurality ofvanes 78 causing impeller 76 to rotate in the direction shown by arrow85. Such motion of impeller 76 also causes shaft 80 to rotate. Shaft 80extends outward from body 71 to provide a drive shaft for a connectedpump. The pressurized fluid passes through cavity 83 to outlet fluidchannel 74.

When vane pump assembly 70 is utilized as a pump, shaft 80 causesimpeller 76 to rotate. As the impeller 76 rotates and a second,unpressurized fluid enters the pump, the vanes 78 are pushed to the wallof body 71 forming a tight seal. As impeller 76 rotates, the vanes forcesuch second fluid into the crescent-shaped cavity, and sweep the fluidtoward the fluid outlet channel 74.

Other combinations of fluid motors and pumps having a common rotatingshaft shared between the motor and pump can be used, such as a gearmotor, as described with reference to FIGS. 1 and 2, and a vane pump, asdescribed above. In such a case, the shaft of one of the gears in thegear motor drives the impeller of the vane pump. In another embodiment,a vane pump assembly can be used as a fluid motor with its shaftconnected to drive one of the gears of a gear pump. Other motorassemblies and/or pump assemblies of generally similar construction maylikewise be utilized, such as a flexible vane pump, a screw pump, asshown in FIGS. 6 a and 6 b, etc.

Referring to FIGS. 7 a and 7 b, a reciprocating-type fluid motor,indicated generally as 125, is shown. Reciprocating motor 125 comprisesa plurality of at least three drive units 127, 128, 129 each including apiston movable within a cylinder; and a valve assembly 132 forcontrolling the introduction of pressurized fluid into the cylinder ofthe respective drive unit and the discharge of spent fluid therefrom fordriving the piston of the respective drive unit; each of the pistonsbeing coupled to the drive shaft 135 such that the pistons initiatetheir respective forward strokes at different angular positions of thedrive shaft.

According to one preferred embodiment, the drive units 127, 128, 129 andvalve assembly 132 are arranged in a linear array with the valveassembly 132 at one end of the respective drive unit and in abuttingrelation to the valve assembly of the adjacent drive unit, and with thedrive shaft 135 coupled to the pistons at the opposite ends of the driveunits. In the described embodiment, the pistons of the drive units arecoupled to the drive shaft 135 via a crankshaft 138 that includes acrank arm for each piston. Such a construction thus permits any desirednumber of drive units to be coupled to the drive shaft 135 in a modularmanner according to the force requirements for any particularapplication. Preferably, the drive shaft 135 includes a single crank armto which the pistons of all the drive units are pivotally coupled. Sucha construction is particularly advantageous in that it permits the driveunits to be coupled, in a convenient and compact manner, to a commondrive shaft of a rotary device.

In FIG. 7 a, crankshaft 138 comprises three cranks 141, 142 and 143.Corresponding to each of cranks 141, 142 and 143, the motor 125comprises three connecting-rod assemblies, which comprise pistons 147,148 and 149, and cylinders 151, 152 and 153. Valve assembly 132comprises valves 156, 157 and 158 having fluid inlet port 161 and fluidoutlet port 162. Valves 156, 157 and 158 serve as pivots of theconnecting-rod assemblies, being inserted respectively into sleeves 166,167 and 168. Valves 156, 157 and 158 can be designed as one unit. FIG. 7b shows the pivotal connections between the pistons 147, 148 and 149 andthe crankshaft 138. In some embodiments, motor 125 may include ahousing, such as shown at 173.

In yet another embodiment, as shown in FIG. 8, gear pump body 42 ispivotally mounted to cover 18 of fluid motor assembly 12 via a pivotscrew 90. When tightened, screw 90 locks the position of gear pump body42, but when loose, screw 90 allows gear pump body 42 to pivot freelyabout screw 90. Once again, shaft 34 extends upward from first gear 30in fluid motor assembly 12, and a motor drive axel 39 extends throughcover 18. Mounted on the exposed end of motor drive axel 39 is a firstdrive train gear 91. As described above, application of a pressurizeddriving fluid through fluid motor assembly 12 will cause rotation ofgear 30, in turn causing rotation of drive shaft 39 and first gear 91mounted thereon. While in the particular embodiment shown in FIG. 8,fluid motor assembly 12 comprises gears 30, 31, as explained above,alternate fluid motor configurations could likewise be utilized withoutdeparting from the spirit and scope of the invention, including a vanepump, flexible rotor pump, gear pumps having gears of other geometries,piston pump, and any other pump assembly which may be driven viaapplication of a pressurized fluid to the flow channel passingtherethrough.

In the particular embodiment depicted in FIG. 8, gear pump body 42 maybe constructed to provide an opening between the bottom of gear pumpbody 42 and cover 18 of fluid motor assembly 12, such opening being ofsufficient size to accommodate first gear 91 and a second gear 92. Inthe embodiment of FIG. 8, gear pump body 42 is depicted as optionallyutilizing a flexible vane pump assembly 70 having a flexible rotor 76mounted within gear pump body 42, with a fluid inlet 95 and fluid outlet96 directing fluid through gear pump body 42 and the open chamber 94thereon holding flexible rotor 76 (FIG. 9). In such case, flexible rotor76 would preferably be mounted on pump drive axel 93, which in turn ismounted to second gear 92, such that rotation of second gear 92 causesrotation of flexible rotor 76 to in turn pump fluid through the pumpassembly. Of course, as explained above, alternate gear elements (suchas one or more parallel tooth gears) may be used for the pump assemblywithout departing from the spirit and scope of the invention.

Because gear pump body 42 is pivotally mounted to cover 18, access maybe had to both first gear 91 and second gear 92 by pivoting gear pumpbody 42. Preferably, first gear 91 is removably attached to drive axel39, such that first gear 91 may be removed and replaced with a gearhaving a different gear geometry, thus enabling gross modification ofthe rotational speeds of gears 30, 31 and of flexible rotor 76, which inturn modifies the proportional flow rates between the fluid motorassembly 12 and the gear pump assembly 15.

Alternately, or in addition to the above, second gear 92 may likewise beremovably attached to flexible rotor 76, such that second gear 92 may bereplaced instead of or in addition to first gear 91 to enable grossmodification of the proportional flows between fluid motor assembly 12and gear pump assembly 15. Still further, first and second gears 91 and92 may be maintained, and gear pump body 42 may be interchangeable witha second pump body 44, as shown in FIG. 10, having fluid inlet 97 andfluid outlet 98 directing fluid through pump body 44 and the openchamber 99 thereon holding a different rotor 79 or other gear members ofvarying construction in different gear pump bodies. The single screwconnection provided by pivot screw 90 enables quick interchange of suchalternate pump body configurations.

Likewise, while not particularly shown in FIG. 8 or 9, gear pumpassembly 15 may be provided with recirculation channel 58 and valve 60,as discussed above, to also enable fine adjustment of the proportionalflows between fluid motor assembly 12 and gear pump assembly 15.

In yet another aspect of the invention, and as particularly shown inFIG. 11, instead of providing the fluid motor with cylindrical gears, inorder to account for variable clearances that may result from tolerancesin the manufacturing process without exorbitantly increasingmanufacturing costs, the gear members 30 and 31 may be provided asround, parallel tooth gears having a tapered perimeter 101. In thiscase, the benefits of using a positive displacement pump as the fluidmotor may be maintained without the associated disadvantages of leakagepast the motor gears. More particularly, the positive displacement pump,and more particularly a gear pump, allows the fluid that drives themotor to likewise provide the lubrication for the gears and rotatingshafts. Gears are quite common and easily manufactured whether bymachining or, for low cost, molding from plastics or sintered from metalpowders. However, for mixing or metering applications, it is desirablethat there be little or no leakage past the gears by the driving fluidin order to obtain maximum output torque of the motor, and in mixingapplications, that a repeatable and constant amount of driving fluidpasses through the pump for each revolution of the gear set. To minimizeleakage past the motor gears, it is advisable to have very closeclearance fits between the perimeter of the gear teeth and the circulargear housing, and to have very little side clearance between the sidesof the gears and the housing. In order to provide minimal clearancewithout exorbitantly increasing the manufacturing costs and risking highfriction conditions (which in turn could render it difficult to startthe fluid motor at low fluid pressure), the gear members in fluid motorassembly 12 are formed as parallel tooth gears having a tapered orcone-shaped perimeter 101. The chambers in which tapered gears 30 and 31sit is likewise preferably tapered so that the gears 30 and 31 can beindividually placed in the tapered housing to a depth that would ensurea close fit regardless of manufacturing tolerances. Notably, suchmanufacturing tolerances may cause a clearance to be produced betweenthe top and bottom walls of the gears and the top and bottom walls ofthe chamber, respectively. Such clearances are preferably filled withupper and lower flat shims 102 to the required thickness, thus resultingin close clearances between both the outside diameters of the gears aswell as between the gear faces and the motor housing.

Operation of the blending pump assembly of the present invention willnow be described with reference, for exemplary purposes, to theparticular embodiment shown in FIG. 1 and the schematic drawings in FIG.12. The fluid motor assembly 12 is driven by fluid pressure from a firstfluid 105 directed through inlet fluid channel 21. Thus, in theparticular embodiment depicted in FIG. 1, it is the flow of fluid thatdrives the first pair of gears 30, 31 in gear motor assembly 12, asopposed to driving the gears to cause fluid to flow. Gears 30, 31 aremeshed together and counter-rotate relative to each other when the firstfluid 105 is directed through the inlet fluid channel to the outletfluid channel 24. Shaft 34 from one of the fluid pressure driven gears,gear 30, extends upward through the housing to drive one of the gears,gear 46 of the gear pump assembly 15, which in turn will cause the gears46, 47 in gear pump assembly 15 to counter rotate relative to each otherin order to draw a second fluid 107 through inlet port 51 and pump suchsecond fluid 107 out through outlet port 52.

It can be seen, therefore, that flow of such first fluid 105 enables thepumping of such second fluid 107 since one gear of each pair is securedto a common rotating shaft. The first pair of gears and second pair ofgears are sized to provide a predetermined proportion of such secondfluid 107 based on the flow of such first fluid 105. The proportionalflow of the second fluid in relation to the first fluid may be finelyadjusted by adjusting the amount of flow through recirculation channel58 by use of valve 60. Since pump assembly 15 provides a positivedisplacement gear pump, increased flow through recirculation channel 58results in decreased flow through outlet port 52. Additionally, theproportional flow may be grossly adjusted by changing the gears in thegear train between fluid motor drive axel 39 and fluid pump drive axel93 (or by replacing gear pump body 42 with an alternate gear pump bodyhaving a distinct gear or rotor configuration) to enable a single pumpassembly to be used in a wide variety of mixing applications.

As shown in the schematic view of FIG. 12, the combined fluid motor/pumpapparatus 10 thus enables the proportional mixing of two distinctfluids, wherein the fluid pressure from the first fluid 105 serves as adriving force for a pump to pump a second fluid 107. Blending pumpassemblies may be combined in series, such that the mixture from a firstassembly 111 may be continuously diluted by directing the mixturethrough a second assembly 114, while directing the driving fluid througha second non-driven (or fluid pressure driven) motor with a commonrotating shaft.

The invention has been described with references to a preferredembodiment. While specific values, relationships, materials and stepshave been set forth for purposes of describing concepts of theinvention, it will be appreciated by persons skilled in the art thatnumerous variations and/or modifications may be made to the invention asshown in the specific embodiments without departing from the spirit orscope of the basic concepts and operating principles of the invention asbroadly described. It should be recognized that, in the light of theabove teachings, those skilled in the art could modify those specificswithout departing from the invention taught herein. Having now fully setforth the preferred embodiments and certain modifications of the conceptunderlying the present invention, various other embodiments as well ascertain variations and modifications of the embodiments herein shown anddescribed will obviously occur to those skilled in the art upon becomingfamiliar with said underlying concept. It is intended to include allsuch modifications, alternatives and other embodiments insofar as theycome within the scope of the appended claims or equivalents thereof. Itshould be understood, therefore, that the invention may be practicedotherwise than as specifically set forth herein. Consequently, thepresent embodiments are to be considered in all respects as illustrativeand not restrictive.

1. A system for blending fluids, comprising: a fluid motor housinghaving a fluid motor with a rotatable drive axle extending through thefluid motor housing; a first fluid pump housing having a first fluidpump rotatable element positioned within an interior of the first fluidpump housing and isolated from fluid flow with the fluid motor, and afirst fluid pump inlet channel and a first fluid pump outlet channel influid communication through the first fluid pump housing; and anintermediate drive assembly between and engaging said drive axle andsaid first fluid pump rotatable element such that torque generated bythe fluid motor is transferred to the first fluid pump rotatable elementthrough said drive axle and said intermediate drive assembly.
 2. Thesystem of claim 1, wherein said first fluid pump housing is pivotallyattached to said fluid motor housing.
 3. The system of claim 2, whereinsaid first fluid pump housing is removable from said fluid motorhousing.
 4. The system of claim 2, further comprising a pivot screwextending through said first fluid pump housing and into said fluidmotor housing, said pivot screw maintaining a pivoting connectionbetween said fluid motor housing and said first fluid pump housing whenloosened, and said pivot screw further maintaining a fixed connectionbetween said fluid motor housing and said first fluid pump housing whentightened.
 5. The system of claim 1, said intermediate drive assemblyfurther comprising a drive train having a first gear connected to saiddrive axle and a second gear connected to said first fluid pumprotatable element, wherein said first gear and said second geardrivingly engage one another.
 6. The system of claim 1, furthercomprising a second fluid pump housing having a second fluid pumprotatable element positioned within an interior of the second fluid pumphousing, and a second fluid pump inlet channel and a second fluid pumpoutlet channel in fluid communication through the second fluid pumphousing, said second fluid pump housing being configured for removableand pivoting attachment to said fluid motor housing to replace saidfirst fluid pump housing, wherein replacing said first fluid pumphousing with said second fluid pump housing results in change inproportional flow of fluids through said system.
 7. The system of claim6, wherein said second fluid pump rotatable element is configured toprovide a different volumetric flow through said second fluid pumphousing for a single revolution of said second fluid pump rotatableelement from a volumetric flow through said first fluid pump housing fora single revolution of said first fluid pump rotatable element.
 8. Ablending pump comprising: a fluid motor having a fluid motor inletchannel and a fluid motor outlet channel operatively connected to afluid motor rotatable motive element, and a drive axle connected to thefluid motor rotatable motive element; a fluid pump having a fluid pumprotatable motive element positioned within an interior of the fluidpump, a fluid pump inlet channel and a fluid pump outlet channel influid communication with the interior of the fluid pump, the fluid pumprotatable motive element of the fluid pump being operatively connectedto the drive axle such that torque generated by the fluid motorrotatable motive element is translated to the fluid pump rotatablemotive element in the fluid pump; and a flow control device controllinga recirculation channel in fluid communication with the fluid pump,wherein the fluid motor rotatable motive element and the fluid pumprotatable motive element provide a proportional fluid flow through thefluid motor and the fluid pump regardless of a rotation rate of thefluid motor rotatable motive element and a rotation rate of the fluidpump rotatable motive element.
 9. The blending pump of claim 8, furthercomprising a first fluid source containing a pressurized first fluidconnected to the fluid motor inlet channel and the fluid pump inletchannel is connected with a second fluid source.
 10. The blending pumpof claim 8, further comprising a seal for preventing leakage between thefluid motor and the fluid pump.
 11. The blending pump of claim 8,wherein the re-circulation channel is in fluid communication with atleast one of the fluid pump inlet channel and the fluid pump outletchannel.
 12. The blending pump of claim 8, wherein the flow controldevice is a needle valve adjustable utilizing a valve stem.
 13. Theblending pump of claim 8, wherein the fluid pump is modular andremovable from and connectable to one or more fluid motors.
 14. Theblending pump of claim 1, wherein the fluid pump is pivotally mounted tothe fluid motor.
 15. A blending pump comprising: a fluid motor having afluid motor inlet channel and a fluid motor outlet channel in fluidcommunication with the fluid motor, and a drive axle connected to saidfluid motor; a first fluid pump having a first plurality of fluid pumpgears positioned on an interior of the first fluid pump and isolatedfrom fluid flow with the fluid motor, and a first fluid pump inletchannel and a first fluid pump outlet channel in fluid communicationthrough the first fluid pump; and an intermediate drive assembly betweenand engaging said drive axle and one of said first fluid pump gears suchthat torque generated by the fluid motor is transferred to the fluidpump gears through said drive axle and said intermediate drive assembly.16. The blending pump of claim 15, wherein said first fluid pump housingis removably attached to said fluid motor.
 17. The blending pump ofclaim 16, further comprising a pivot screw extending through said firstfluid pump and connected to said fluid motor, said pivot screwmaintaining a pivoting connection between said fluid motor and saidfirst fluid pump when loosened, and said pivot screw further maintaininga fixed connection between said fluid motor and said first fluid pumpwhen tightened.
 18. The blending pump of claim 15, said intermediatedrive assembly further comprising a drive train having a first gearconnected to said drive axle and a second gear connected to one of saidfirst fluid pump gears, wherein said first gear and said second gear ofsaid drive train drivingly engage one another.
 19. The blending pump ofclaim 15, further comprising a second fluid pump having a secondplurality of fluid pump gears positioned within an interior of thesecond fluid pump, and a second fluid pump inlet channel and a secondfluid pump outlet channel in fluid communication through the secondfluid pump, said second fluid pump being configured for removable andpivoting attachment to said fluid motor to replace said first fluidpump, wherein replacing said first fluid pump with said second fluidpump results in change in proportional flow of fluids through saidblending pump.
 20. The system of claim 19, wherein said second pluralityof fluid pump gears is configured to provide a different volumetric flowthrough said second fluid pump for a single revolution of said secondpair of fluid pump gears from a volumetric flow through said first fluidpump for a single revolution of said first plurality of fluid pumpgears.